1. Field of Invention
This invention is directed generally toward rollers used on machines and more specifically toward rollers used on machinery in the harvesting of agricultural products.
2. Discussion of Related Art
Conveyors are commonly used during the harvesting and processing of agricultural products. Harvesters used in the harvest of such crops as potatoes, sugar beets, onions and carrots employ such conveyors. These conveyors are designed to shed dirt as they convey produce from the ground to the truck, for example. In processing applications, these conveyors also shed dirt, sand and other unwanted objects as they convey the produce. Examples of rollers employed with such conveyors are shown in U.S. Pat. Nos. 5,454,460 and 5,722,888. Due to the location required to support these conveyors, the dirt, sand and other materials shed from these conveyors tends to fall directly onto these rollers. Most often the rollers eventually fail due to contaminants getting to the bearings within the rollers. In fact, those rollers rarely fail for any other cause.
Prior art rollers are bored axially for the placement of radial ball bearings to support the load of the roller. Additionally, there may be other devices placed outboard of the bearing to offer greater sealing against contaminants. Typically, there will be a bushing placed through the bearing's bore to size for an axle which is usually a bolt that attaches the roller to the frame of the harvester. These bushings typically extend beyond the length of the roller so as to stand the roller off from the frame of the harvester a defined distance. Axial bores in the prior art are parallel to the axle. Consequently, outer dimensions of bushings, also known as “standoffs,” are then parallel to the axle. The dimensions of the standoffs or bushings are horizontal, allowing for an easy migration of contaminants along the topside of the standoff into the bearing housing.
Another problem existing with conventional rollers is with dirt or mud packing up on the standoff and eventually forcing its way beyond any additional sealing device and into the bearing bore. Eventually the contaminant gets into the bearings, causing the roller to fail.